Virtual reality (VR) is a computer-generated reality that creates an illusion in a user, (typically a human) that the user is in a virtual or an artificially created world. Virtual reality may stimulate naturally occurring senses such as for example, sight, sound, tactile, haptic, and/or movement. Actions of the user are translated by the computer into inputs that effect the virtual environment in which the user is in.
Virtual reality has been proven to be a useful and beneficial science and currently is being used to help people overcome the fear of heights, fear of flying, and as training devices for pilots of all kinds of vehicles; tanks, planes, helicopters, etc. For example, current VR systems are used to allow pilots of vehicles the increased ability to totally immerse into virtual environments (VEs). The three most critical senses required for total immersion are already built into the vehicle itself for such pilot training. Sight, sound, and tactile are considered the three most critical—smell and taste could also be considered but are considered a finer sensory stimulus and thus, considered as having a secondary level of impact on the human's immersion in virtual reality.
Virtual reality (VR) typically employs computer-generated stimulation of the human senses to simulate naturally occurring inputs such as sight and sound. Additional sensations which may be stimulated may include orientation, balance, and touch and force (haptic) feedback. A complete and immersive VR experience generally simultaneously stimulates a user with sight, sound, touch, and movement. However, a major limitation in current state-of-the-art VR is the inability to permit the user to safely navigate, for example via simple walking and running in a physical space that may be confined while experiencing the VR environment.
Navigation in such known systems is typically experienced as a disembodied center of consciousness which is directed by pointing, other gesture or by manipulation of a joystick, trackball, mouse, or similar device. The actual physical sensation of walking is limited to forms such as the user is restricted to a confined and immobile surface where tracking and signal generation are well-controlled, or the user is confined to a device such as a linear treadmill or wheelchair which simulates the user's linear motion from real space to virtual space. The conventional linear treadmill may include a movable track which may optionally be upwardly inclined. However, the linear track is only movable in one direction which restricts motion of the user to the direction of movement of the track as designed.
Such use of a linear treadmill in a virtual environment generally consists of one continuous moving track, and in conjunction with an external monitor or head mounted-display, permits a user to walk in a straight line. However, the user cannot step in arbitrary directions as s/he would be able to in real life. This limitation in navigation detracts from the immersive nature of the experience, and requires that the experience takes on more of a vehicular nature rather than that of free locomotion by freely walking and navigating body.
Another type of treadmill implemented in virtual reality environments is an omni-directional treadmill apparatus that allows a user, typically a person, to move, walk, run or crawl in any arbitrary direction. The apparatus has a frame for supporting the apparatus on a fixed surface. A track assembly mounted on the frame provides a user support that moves in a direction determined by directional orientation of the user on the track assembly. The track assembly has a user support movable in first direction by a first drive motor. The user support includes user support members rotatable about axes generally normal to the direction of movement of the support. It may also include a power driven endless belt, engages the user support members to rotate the user support members whereby the combined movement of the user support members and user supports results in omni-directional user movement. Controls on the user may be provided responsive to the directional orientation of the user which in turn controls the directional user movement to conform the orientation of the user on any such user supports.
However, a major limitation in such virtual reality systems is an inability for the system to allow natural human locomotion. Navigation is typically experienced as an unnatural and disembodied center of consciousness directed by for example, pointing, other gestures or by manipulation of a joystick, trackball, mouse, or similar device. The user, through the use of a head mounted display, is provided sensory information that the user is moving, but the user is located within the confines of a virtual reality pod, restraint or treadmill type system, and cannot physically move freely. Furthermore, disadvantageously, these known systems often cause discomfort, nausea, and even motion sickness in users.
Other virtual reality systems comprise a treadmill that is connected to a computer system. This treadmill approach is very similar to known virtual reality pods except that the user is allowed uni-directional movement only. The user can walk forward and the virtual reality will respond accordingly. However, the user is unable to move backwards or side to side. Again, such a system does not allow for natural human locomotion and causes disorientation and potentially nausea in some users.
Still other approaches implement using a treadmill that is able to move in both forward and reverse directions, as well as move from left to right. The user walks in a desired direction while sensors are positioned to detect which direction the user has walked. These sensors respond to signals transmitted from devices attached to the user's hands, waist, etc. The treadmill is then moved in the appropriate directions to continually bring the user back to the center of the treadmill. Motors are used that move the treadmill forward or backwards and left or right. Thus, the treadmill system senses movement and then reacts by moving the treadmill in such a manner to reposition the user in the center of the treadmill.
Oftentimes, expensive motors are required in such VR systems, and more importantly, the system must physically move the user resulting in a potentially “jerky” or even unsafe motion as the user is repositioned in the center of the treadmill. If the user moves too quickly, e.g. beyond the pace of a walk, the system may not react in time and the user may actually walk off of the treadmill or the system may attempt to quickly move the user back to the center of the treadmill and “jerk” the user. Again, as with other systems, this motion may cause disorientation and nausea in some users. Furthermore, if the user trips or loses his or her balance while using the treadmill, the user may experience falling and injury. Falling and loss of balance can occur in such systems since the user cannot actually “see” the physical treadmill, only the virtual world presented. Thus, if the user experiences any loss of balance, which is typical in such systems, the user has difficulty recovering balance and may fall.
Still other known virtual reality systems implement a user support that is rigidly secured above a sphere and supports a user on the exterior surface of the sphere and holds a center of mass of the user on a vertical axis passing through the sphere. Additionally, one or more sensors may be coupled to the base support to detect and measure a movement of the sphere. In addition, a harness and restraining support must be used in conjunction with the system to hold the user in position along one axis, while allowing for rotation when on the exterior surface of the sphere.
Yet other known virtual reality systems provide a system in which individuals can experience both visual and physical immersion into virtual environments by performing human locomotive characteristics such as walking, running, crawling, jumping, climbing, etc. in a stationary or confined space while visually interacting with a VR system and physically interacting with a mobility platform system. These devices may further provide a device designed to work in conjunction with a VR system where the user can navigate through different environments, while staying in one place, and view the changes in the environment commensurate with the amount of movement performed. Such systems again may allow a mode that would simulate locomotive functions (similar to treadmills) where one can endure locomotive exercise, yet remain in a relatively stationary position, safely. Such systems may include calibration strips with electromagnetic locomotion platforms to monitor foot movements albeit, in a stationary position. The drawback of such VR systems include side effects such as nausea and further, the inability of the user to move freely and safely in a physical environment.
Therefore, it is desirable to implement a system and method that permits real walking which results in higher immersive presence for virtual reality (VR) applications than alternative locomotive means such as walking-in-place and external control gadgets, but takes into account different room sizes, wall shapes, and surrounding objects in the virtual and real worlds. Despite perceptual study of impossible spaces and redirected walking, there are no known general methods that can effectively match and map a given pair of virtual and real scenes. Devising such mapping remains a drawback in existing VR display and navigation systems.
It is further desirable to implement a system and method in virtual reality (VR) applications, that permits real walking or jogging, rather than alternative locomotive means such as walking-in-place and/or external control devices. In order to offer a more immersive experience, real walking VR applications accommodate different room sizes, wall shapes, and surrounding objects in the virtual and real worlds. It is further desirable to implement a system and method that matches virtual and physical worlds thereby permitting immersive VR walk. The desired system and method enables free walking when users are using a known head-mounted display (HMD) while walking in a real space and display of a virtual space that the users perceive through the HMD. It is further desirable to implement a system and method that guides user navigation within the physical environment while retaining visual fidelity to the virtual environment.
It is yet further desirable to implement a system and method that preserves the virtual world appearance while the user is actually walking or navigating within the confines of the physical world geometry, yet retaining a comfortable balance between visual fidelity and navigation comfort. Such desired system and method may be utilized in applications ranging from medical applications such as training dementia patients, gaming such as first-person active gaming, educational such as architecture walkthrough, and other medical imaging applications. It is further desirable to implement a system and method that matches a given pair of virtual and physical worlds in a progressive and dynamic mapping system for immersive VR navigation.
It is further desirable to implement a system and method that can determine a planar map between the virtual and physical floor plans, that can minimize angular and distal distortions while conforming to the virtual environment goals and within the confines and any additional physical environment constraints. It is further desirable to implement a system and method that determines and designs maps that are globally surjective and permit the proper folding or compressing of large virtual scenes into smaller real scenes. It is further desirable to implement a system and method that is also locally injective to avoid locomotion ambiguity and intersecting virtual objects that exist in known virtual reality systems.
It is further desirable to implement a system and method that can implement these derived maps with an altered and progressive rendering to guide user navigation within the physical environment constraints and any confines, while retaining visual fidelity to the virtual environment.
It is further desirable to implement a system and method that effectively warps, folds and further refines the virtual world appearance as mapped into the real world geometry as mapped with greater visual and enhanced visual solutions and performance.